Difference in Vitamin B-2 & Vitamin B-3

Almonds are a rich source of vitamin B-2, while peanuts provide vitamin B-3.

You need both vitamin B-2, or riboflavin, and vitamin B-3, or niacin, in your diet. Both help convert the carbohydrates you eat into glucose, the sugar your body burns for fuel. Both are water-soluble, meaning your body doesn’t store them and you have to get them from diet. But riboflavin and niacin differ in how much you need of each, which foods provide them and their specific functions.

Daily Requirements

The body needs higher amounts of niacin than riboflavin. The recommended daily allowance for niacin in adults is 14 to 16 milligrams, while the RDA for riboflavin is 1.1 to 1.3 milligrams. Most people get enough of both vitamins from food.

Sources

Brewer's yeast is a good source of both vitamins. So are fortified cereals and breads made from fortified flour. For vitamin B-2, look to almonds, organ meats, whole grains, wild rice, mushrooms, soybeans, milk, yogurt, eggs, broccoli, Brussels sprouts and spinach. You’ll get plenty of vitamin B-3 from beets, beef liver, fish, sunflower seeds and peanuts. Because your body converts the amino acid tryptophan into niacin, poultry, red meat, eggs and dairy products -- all rich in tryptophan -- are good sources of vitamin B-3.

Cooking and Storage

Light destroys riboflavin, so to preserve the vitamin, store foods covered or in a produce bin or cupboard. Niacin is not light-sensitive. Both B-2 and B-3 dissolve in water, so frying, roasting, grilling or steaming foods is better than boiling for preserving the vitamins.

Functions and Benefits of Vitamin B-2

Riboflavin is an antioxidant, a substance that fights cell damage. The body also needs vitamin B-2 to convert vitamin B-6 and folate into usable forms. The University of Maryland Medical Center cites one study in which people who suffered migraines cut the number of their attacks in half by taking 400 milligrams of riboflavin a day. However, more research is needed.

Functions and Benefits of Vitamin B-3

With the help of niacin, your body produces hormones in the adrenal glands and elsewhere. Niacin also helps circulation. Niacin supplements may help reduce cholesterol and levels of triglyceride, a type of fat. According to the Linus Pauling Institute, niacin might help prevent mouth, throat and esophageal cancer, and reduce the number of heart attacks and strokes in men who have already had a heart attack, but the evidence is still evolving.

Vitamin B-2 Safety

Riboflavin is considered safe even at high doses, according to the University of Maryland Medical Center, although taking more than 10 milligrams a day can make your eyes more sensitive to the sun. If you’re taking a lot of riboflavin in supplement form, wear sunglasses.

Vitamin B-3 Safety

Niacin, which doctors sometimes prescribe for lowering cholesterol or treating other conditions, has annoying side effects and can be toxic in large doses. Niacin can cause flushing of the skin, upset stomach, headache, dizziness, blurred vision and even liver damage. Take niacin supplements only under the supervision of a health-care professional.

About the Author

From 1978 until 1995, Virginia Van Vynckt worked as a writer and editor at The Chicago Sun-Times. She has written extensively about food and nutrition, having co-authored seven cookbooks. She also published "Our Own," a book about older-child adoption. Van Vynckt holds a Bachelor of Arts degree in journalism from Indiana University.